fix: duplicate tar copying (#576)

examples/assertion/BUILD.bazel

@@ -0,0 +1,57 @@
+load("@aspect_bazel_lib//lib:tar.bzl", "tar")
+load("@bazel_skylib//rules:build_test.bzl", "build_test")
+load("//oci:defs.bzl", "oci_image")
+
+# Case 1: image name containing a capital case.
+oci_image(
+    name = "imagE",
+    architecture = "amd64",
+    cmd = ["noop"],
+    os = "linux",
+)
+
+# Case 2: existing layer added again.
+tar(
+    name = "empty_tar",
+    srcs = [],
+)
+
+oci_image(
+    name = "same_tar_multiple_times",
+    architecture = "amd64",
+    cmd = ["noop"],
+    os = "linux",
+    tars = [
+        ":empty_tar",
+    ],
+)
+
+oci_image(
+    name = "case2",
+    base = ":same_tar_multiple_times",
+    tars = [
+        ":empty_tar",
+    ],
+)
+
+# Case 3: Adding an identical tar from another directory multiple times
+oci_image(
+    name = "case3",
+    architecture = "arm64",
+    os = "linux",
+    tars = [
+        # layer_0 and layer_1 is identical
+        "//examples/just_tar:layer_0",
+        "//examples/just_tar:layer_1",
+    ],
+)
+
+# build them as test.
+build_test(
+    name = "test",
+    targets = [
+        ":imagE",
+        ":case2",
+        ":case3",
+    ],
+)

examples/assertion/README.md

@@ -0,0 +1 @@
+This directory is not useful as an example, merely exists for test coverage.

examples/big_image/README.md

@@ -0,0 +1 @@
+This directory is not useful as an example, merely exists for test coverage.

examples/just_tar/BUILD.bazel

@@ -0,0 +1,20 @@
+load("@aspect_bazel_lib//lib:tar.bzl", "tar")
+
+# See `Case 3` in examples/assertion
+genrule(
+    name = "10mb_file",
+    outs = ["10mb_file.out"],
+    cmd = "head -c 10485760 < /dev/urandom > $@",
+    local = True,
+    tags = ["manual"],
+)
+
+[
+    tar(
+        name = "layer_%s" % i,
+        srcs = ["10mb_file"],
+        tags = ["manual"],
+        visibility = ["//examples/assertion:__pkg__"],
+    )
+    for i in range(2)
+]

examples/just_tar/README.md

@@ -0,0 +1 @@
+This directory is not useful as an example, merely exists for test coverage.

examples/simple/README.md

@@ -0,0 +1 @@
+This directory is not useful as an example, merely exists for test coverage.

oci/private/image.sh

@@ -102,13 +102,15 @@ function add_layer() {
       --arg media_type "${media_type}" | update_manifest
 
   local digest_path= 
+  local output_path=
   digest_path="$(jq -r '.digest | sub(":"; "/")' <<< "$desc")"
+  output_path="$OUTPUT/blobs/$digest_path"
 
   if [[ "$USE_TREEARTIFACT_SYMLINKS" == "1" ]]; then
     relative=$(coreutils realpath --no-symlinks --canonicalize-missing --relative-to="$OUTPUT/blobs/sha256" "$path" )
-    coreutils ln -s "$relative" "$OUTPUT/blobs/$digest_path"
+    coreutils ln --force --symbolic "$relative" "$output_path"
   else
-    coreutils cat "$path" > "$OUTPUT/blobs/$digest_path"
+    coreutils cat "$path" > "$output_path"
   fi
 }
 

oci/private/push.bzl

@@ -186,7 +186,7 @@ oci_push_lib = struct(
     attrs = _attrs,
     toolchains = [
         "@rules_oci//oci:crane_toolchain_type",
-        "@aspect_bazel_lib//lib:yq_toolchain_type",
+        "@aspect_bazel_lib//lib:jq_toolchain_type",
         "@bazel_tools//tools/sh:toolchain_type",
     ],
 )